Meta Information
ID:selenium
Name:
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-05-21T22:30:00Z
Model
phase-a-upgrade-claude-sonnet-4.6
Interactions
Target id:
/condition/renal-impairment
Target name:
Renal Impairment
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
The kidneys are responsible for excreting excess selenium. In individuals with severe kidney disease, selenium can accumulate to toxic levels, a condition known as selenosis.
Actionable advice:
Selenium supplements should be avoided with severe kidney disease unless specifically directed by a nephrologist.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The 24 h selenium excretion is dependent on the glomerular filtration rate of the kidney characterized by the creatinine clearance. This result is important, because if the selenium excretion is used as parameter for the selenium status of humans, the kidney function should be known. This is a limitation for the use of the urinary selenium excretion as parameter for the selenium status. This is especially important for patients whose glomerular filtration rate is low.
Label source:
PubMed: Biological trace element research (1990)
Source url:
Exact phrase from label:
Studies of bioavailability and balance show the important role of the kidneys in homeostatic regulation of Se.
Label source:
PubMed: Clinical chemistry (1993)
Source url:
Exact phrase from label:
The liver is the central organ for selenium regulation and produces excretory selenium forms to regulate whole-body selenium.
Label source:
PubMed: Annual review of nutrition (2015)
Action type:
avoid
Target id:
/condition/iodine-deficiency
Target name:
Iodine Deficiency
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
In the presence of iodine deficiency, high selenium intake can exacerbate hypothyroidism by increasing the conversion of T4 to T3, which rapidly depletes the body's scarce thyroid hormone stores.
Actionable advice:
Iodine status should be adequate before starting high-dose selenium supplementation.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
In selenium-and-iodine-deficient humans, selenium supplementation may aggravate hypothyroidism by stimulating thyroxin metabolism by the selenoenzyme type I iodothyronine 5'-deiodinase.
Label source:
PubMed: The American journal of clinical nutrition (1993)
Source url:
Exact phrase from label:
The results indicated that Se deficiency influenced the conversion of T4 to T3 and induced the accumulation of T4 and FT4.
Label source:
PubMed: Biological trace element research (2014)
Source url:
Exact phrase from label:
Furthermore, when selenium was supplemented in seven patients with abnormal thyroid hormone levels, the TSH, FT4, and FT4/FT3 ratio were significantly decreased and FT3 levels were increased.
Label source:
PubMed: Clinical pediatric endocrinology : case reports and clinical investigations : official journal of the Japanese Society for Pediatric Endocrinology (2021)
Action type:
informational_none
Target id:
/intervention/iodine
Target name:
Iodine
Severity:
major
Interaction type:
requirement
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Selenium is an essential cofactor for deiodinase enzymes, which are required to convert inactive thyroid hormone (T4) into its active form (T3). Adequate selenium is necessary for proper iodine utilization.
Actionable advice:
Adequate selenium intake should be maintained when supplementing with iodine to support healthy thyroid function.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Selenium is an essential trace element which is part of the active site of seleno-dependent glutathione peroxidase and type 1 deiodinase.
Label source:
PubMed: Selenium status in an iodine deficient population of the West Ivory Coast. (PMID 11385942)
Action type:
informational_none
Target id:
/class/anticoagulants-antiplatelets
Target name:
Anticoagulants and Antiplatelets
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
High doses of selenium (typically above 400 mcg/day) may inhibit platelet aggregation, potentially increasing the risk of bleeding when combined with medications that thin the blood like warfarin, clopidogrel, or aspirin.
Actionable advice:
It is important to consult a doctor before combining, especially with selenium doses over 200 mcg/day.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The data support our hypothesis that antioxidant supplementation of men with low antioxidant status and high fat intake reduces lipid peroxidation, the capacity of platelets to aggregate and to produce thromboxane A2, and in vivo platelet activation.
Label source:
PubMed: Effects of antioxidant supplementation on platelet function: a randomized pair-matched, placebo-controlled, double-blind trial in men with low antioxidant status. (PMID 1826987)
Action type:
informational_none
Target id:
/condition/diabetes-mellitus
Target name:
Diabetes or High Risk for Diabetes
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Some large-scale clinical trials and observational studies have linked long-term supplementation with selenium (typically 200 mcg/day or more) to an increased risk of developing type 2 diabetes.
Actionable advice:
Long-term, high-dose selenium supplementation is best avoided by those who have or are at high risk for diabetes.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
We also computed a RR for diabetes incidence following supplementation with 200 µg/day of selenium compared with placebo in trials.
Label source:
PubMed: Selenium exposure and the risk of type 2 diabetes: a systematic review and meta-analysis. (PMID 29974401)
Action type:
avoid
Target id:
/condition/history-of-skin-cancer
Target name:
History of Non-Melanoma Skin Cancer
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
The Nutritional Prevention of Cancer (NPC) and SELECT trials observed a small but statistically significant increase in squamous cell carcinoma and total non-melanoma skin cancer in individuals taking selenium supplements.
Actionable advice:
If you have a history of skin cancer, consult your dermatologist before taking selenium supplements.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Although results through the entire blinded period continued to show that selenium supplementation was not statistically significantly associated with the risk of basal cell carcinoma (hazard ratio [HR] = 1.09, 95% confidence interval [CI] = 0.94 to 1.26), selenium supplementation was associated with statistically significantly elevated risk of squamous cell carcinoma (HR = 1.25, 95% CI = 1.03 to 1.51) and of total nonmelanoma skin cancer (HR = 1.17, 95% CI = 1.02 to 1.34).
Label source:
PubMed: Journal of the National Cancer Institute (2003)
Source url:
Exact phrase from label:
In one trial selenium showed a reduced risk of other types of cancer compared with placebo (RR 0.65, 95% CI 0.50 to 0.85) but also a significantly elevated risk of a new NMSC (HR 1.17 95% CI 1.02 to 1.34).
Label source:
PubMed: The Cochrane database of systematic reviews (2007)
Action type:
informational_none
Target id:
/procedure/elective-surgery
Target name:
Elective Surgery
Severity:
moderate
Interaction type:
adverse
Nature:
temporal
Temporal spacing:
Hours before target:
336
Hours after target:
null
Description:
Due to its potential effects on blood clotting, it is often recommended to discontinue high-dose selenium supplementation before scheduled surgery to minimize any potential increase in bleeding risk.
Actionable advice:
Selenium supplements are best stopped at least 2 weeks prior to any scheduled surgery.
Validation status:
validated_via_clinical_guidance
Evidence tier:
tier_b
Evidence basis:
clinical_guidance_verbatim
Evidence anchors:
Exact phrase from label:
the American Society of Anesthesiologists (ASA) and the American Association of Nurse Anesthetists (AANA) recommend stopping herbal medications 1–2 weeks before elective surgical procedures
Label source:
Clinical guidance: ASA/AANA — Perioperative herbal medication discontinuation
Action type:
informational_none
Target id:
/intervention/vitamin-c
Target name:
Vitamin C (Ascorbic Acid)
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
High doses of Vitamin C can chemically reduce inorganic selenium (selenite) to its elemental form in the gut, which is poorly absorbed. This interaction is less significant with organic selenium forms like selenomethionine.
Actionable advice:
High-dose Vitamin C and inorganic selenium (selenite) should be separated by at least 2 hours.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
It is possible that selenite is reduced by vitamin C to elemental selenium and is therefore not available for uptake by tissues.
Label source:
PubMed: Interaction of vitamin C and selenium supplementation in the modification of mammary carcinogenesis in rats. (PMID 3088312)
Action type:
separate
Target id:
/condition/hashimotos-thyroiditis
Target name:
Hashimoto's Thyroiditis
Severity:
moderate
Interaction type:
synergistic
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Selenium supplementation, typically at 200 mcg/day, has been shown in multiple studies to reduce thyroid peroxidase (TPO) antibodies and improve thyroid structure and well-being in individuals with Hashimoto's.
Actionable advice:
If you have Hashimoto's, discuss selenium supplementation with your endocrinologist.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
36 patients received 200 microg (2.53 micromol) sodium selenite/d, orally, for 3 months... The mean TPOAb concentration decreased significantly to 63.6% (P = 0.013) in the selenium group vs. 88% (P = 0.95) in the placebo group.
Label source:
Primary literature: https://pubmed.ncbi.nlm.nih.gov/11932302/
Action type:
informational_none
Target id:
/class/statins
Target name:
Statins (HMG-CoA Reductase Inhibitors)
Severity:
minor
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Some evidence suggests that antioxidant cocktails including selenium, vitamin E, and vitamin C may slightly blunt the HDL-cholesterol-raising benefit of statins, particularly when they are taken with niacin.
Actionable advice:
This interaction is minor and its clinical significance is debated; no action is typically required.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
However, increases in HDL-C, especially HDL(2)-C, were consistently higher in the S-N group than in the S-N+A group (25% vs 18% and 42% vs 0%, respectively).
Label source:
PubMed: Arteriosclerosis, thrombosis, and vascular biology (2001)
Source url:
Exact phrase from label:
The protective increase in HDL2 with simvastatin plus niacin was attenuated by concurrent therapy with antioxidants.
Label source:
PubMed: The New England journal of medicine (2001)
Source url:
Exact phrase from label:
Results of a previous small study (n = 44) suggested that either a combination of an antioxidant cocktail [800 IU/day 2R,4'R,8'R-(RRR)-AT plus 1 g vitamin C, 25 mg beta-carotene, and 100 microg selenium] or individual antioxidant vitamins combined with simvastatin-niacin (S-N) therapy attenuated the protective increase in HDL2 seen with S-N alone.
Label source:
PubMed: Clinical chemistry (2007)
Action type:
informational_none
Target id:
/intervention/zinc
Target name:
Zinc Supplements
Severity:
minor
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
High doses of zinc and selenium can compete for similar absorption pathways in the small intestine, which may slightly reduce the bioavailability of both minerals when taken simultaneously.
Actionable advice:
High-dose zinc and selenium supplements are best separated by at least 2 hours for optimal absorption.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Selenium had an antagonistic effect on zinc absorption by zinc-depleted rats, and zinc had an antagonistic effect on selenium absorption by zinc-adequate rats.
Label source:
PubMed: Bioavailability of and interactions between zinc and selenium in rats fed wheat grain intrinsically labeled with 65Zn and 75Se. (PMID 2746373)
Action type:
separate
Target id:
/intervention/vitamin-e
Target name:
Vitamin E
Severity:
minor
Interaction type:
synergistic
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Selenium, as a key component of the enzyme glutathione peroxidase, and Vitamin E work synergistically to protect cells from oxidative damage in different cellular compartments.
Actionable advice:
Consider taking Vitamin E and selenium in the same regimen to support antioxidant defenses.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Glutathione peroxidase is an important enzyme in destroying H2O2 and organic hydroperoxides such as lipid hydroperoxides. It therefore guards against oxidative damage to the cell membranes and other oxidant-sensitive sites in the cell. While this selenium-dependent system destroys lipid hydroperoxides and other peroxides, vitamin E is believed to protect against oxidant damage to membranes by preventing the formation of lipid hydroperoxides.
Label source:
PubMed: Federation proceedings (1975)
Source url:
Exact phrase from label:
Selenium and vitamin E work together as a team to prevent lipid peroxidation. Vitamin E quenches lipid hydroperoxyl radicals and the resulting lipid hydroperoxide is then converted to the lipid alcohol by selenocysteine-containing glutathione peroxidase.
Label source:
PubMed: Current opinion in chemical biology (2023)
Source url:
Exact phrase from label:
Vitamin E and selenium function synergistically in the myocardium to provide important antioxidant defenses in iron-overload states, including increased concentrations of selenium, increased glutathione peroxidase activity and decreased concentrations of iron.
Label source:
PubMed: The Canadian journal of cardiology (1998)
Action type:
informational_none
Target id:
/dietary/high-mercury-fish
Target name:
High-Mercury Fish (e.g., Tuna, Swordfish)
Severity:
minor
Interaction type:
synergistic
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Selenium has a very high binding affinity for mercury, forming a biologically inert mercury-selenide complex. This interaction can mitigate the toxic effects of mercury exposure from dietary sources.
Actionable advice:
Ensuring adequate selenium intake may be beneficial if your diet is high in mercury-containing fish.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Exact phrase from label:
dietary Se can reduce Hg toxicity by directly interacting with either Hg(II) or methylmercury (MeHg) to form inert products, such as HgSe complexes
Label source:
Primary literature: https://pmc.ncbi.nlm.nih.gov/articles/PMC6726406/
Action type:
informational_none
Target id:
/class/gold-compounds
Target name:
Gold Salts (e.g., Auranofin)
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Gold-based medications, used for conditions like rheumatoid arthritis, can bind to selenium and decrease its levels and the activity of selenoenzymes in the body.
Actionable advice:
If taking gold salts, discuss your selenium status and potential need for supplementation with your doctor.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Auranofin has the capacity to selectively inhibit endogenous antioxidant enzymes thioredoxin reductase (TrxR) and glutathione peroxidase (GPx), resulting in oxidative stress... Significant inhibition of TrxR was observed at 20nM Auranofin
Label source:
Primary literature: https://pubmed.ncbi.nlm.nih.gov/28947276/
Action type:
informational_none